This is a 24 week, double-blind, placebo-controlled, randomized multicenter study to determine the effectiveness and tolerability of the combination of DMP 266 and Indinavir versus Indinavir in HIV-infected patient nucleoside analogue (NRTI) therapy. The objectives of the study is to evaluate the effectiveness of DMP 266 in combination with Indinavir relative to treatment with Indinavir alone on viral load suppression in HIV-infected patients concomitantly receiving NRTIs. To evaluate the tolerability of DMP 266 in combination with Indinavir relative to treatment with Indinavir alone in HIV-infected patients concomitantly receiving NRTIs. A total number of 300 patients will be enrolled. The study duration will be approximately 10 months. At the end of the 24-week period, patients randomized to both treatment groups will be given the option to continue on open-label DMP 266 plus Indinavir.